Berlin  - Oskar Lafontaine, the maverick former Social Democrat (SPD) politician, is to lead the socialist Left party in state elections in Germany's western Saarland next year, after gaining the clear support of Left members in the state Saturday.

Lafontaine, who walked out of the government of former SPD chancellor Gerhard Schroeder in 1999 after just six months as Finance Minister, garnered 122 of 132 votes cast at the party congress held at Neunkirchen in the state.

The leftist leader called on his former party not to enter a coalition with the ruling Christian Democrats (CDU) after the election, to be held in the autumn of 2009.

The SPD is joined in an unwieldy coalition at federal level with Chancellor Angela Merkel's CDU.

Lafontaine, who is scorned by the SPD leadership for walking out of Schroeder's SPD-Greens coalition months after it took office, was premier of Saarland from 1985 to 1998 at the head of an SPD government.

Since leaving the SPD, he has played a key role in the rise of parties on the left of his former political home.

Since its formation little more than a year ago, the Left, based on supporters of formerly communist East Germany and disgruntled SPD members in the west, has grown strongly.

Left party chief in Saarland Rolf Linsler urged party members to aim for "20 per cent plus a large X" in next year's elections. Polls currently give the party close to 20 per cent.

The SPD chairman in the state, Heiko Maas, has made clear that the SPD will not play the part of junior coalition partner to a Left- dominated state government, but has not ruled out cooperation altogether.

The SPD has thus far avoided cooperation with the Left in western states. An SPD-Left coalition is in power in the eastern city-state of Berlin, and SPD leaders in the western state of Hesse have put out feelers to the Left, despite strong misgivings by many SPD members. (dpa)